Definition
CAN bus (Controller Area Network) is a multi-master, broadcast serial communication bus protocol proposed by Bosch in 1986. It has now become the de facto standard for internal communication in automotive electronics, industrial control, and IoT devices. CAN uses differential signaling and a CSMA/CR arbitration mechanism, supporting multi-node bus sharing, high anti-interference capability, and strong real-time performance, and is widely used in EV charging stations, new energy vehicles, logistics vehicles, industrial equipment, and other scenarios.
In electric vehicle and charging scenarios, the CAN bus is used for BMS (Battery Management System), motor controllers, and charging protocol interactions between charging stations and vehicles (such as ISO 15118, GB/T 27930), achieving charging handshake, power negotiation, billing data exchange, and so on.
Technical Features and Architecture
The technical features of CAN bus include: multi-master architecture — any node can initiate communication, with priorities determined by arbitration using identifiers (ID); differential transmission — CAN_H/CAN_L dual-wire differential, resistant to common-mode interference; frame format — standard frame (11-bit ID) and extended frame (29-bit ID), with a maximum data field length of 8 bytes; error detection — mechanisms such as CRC, ACK, and bit stuffing ensure reliability. Common speeds: CAN 2.0 up to 1 Mbps, CAN FD supports higher bandwidth.
In the charging platform architecture, EV charging stations communicate with the vehicle BMS via CAN, while simultaneously using 4G/5G IoT SIM cards to transmit the charging data collected by data acquisition back to the charging operation platform , enabling remote monitoring and billing. In cross-border charging scenarios, charging protocols in different countries may vary slightly and multi-protocol adaptation needs to be supported.
Application in IoT and cross-border scenarios
Applications of the CAN bus in IoT and cross-border scenarios include: new energy vehicles — the whole vehicle CAN network connects the ECU, BMS, instrument panel, etc.; EV charging stations — charging communication with the vehicle BMS and remote data reporting to the charging management platform; logistics vehicles — onboard terminals read OBD data via CAN, combined with positioning to implement route and fuel consumption monitoring; industrial IoT — interconnection of PLCs, sensors, and actuators. Cross-border logistics fleets and cross-border charging networks both rely on CAN data acquisition and IoT transmission. SimtoLink provides stable cross-border connections for onboard terminals and EV charging stations, ensuring reliable CAN data cloud upload.